7. kill (Terminate)

You can send signals that terminate processes, such a command is aptly named the kill command.

$ kill 12445

The 12445 is the PID of the process you want to kill. By default it sends a TERM signal. The SIGTERM signal is sent to a process to request its termination by allowing it to cleanly release its resources and saving its state.

You can also specify a signal with the kill command:

$ kill -9 12445

This will run the SIGKILL signal and kill the process.

Differences between SIGHUP, SIGINT, SIGTERM, SIGKILL, SIGSTOP?

These signals all sound reasonably similar, but they do have their differences.

SIGHUP - Hangup, sent to a process when the controlling terminal is closed. For example, if you closed a terminal window that had a process running in it, you would get a SIGHUP signal. So basically you've been hung up on

SIGINT - Is an interrupt signal, so you can use Ctrl-C and the system will try to gracefully kill the process